Split or portable air conditioner: which is right for you?

Portable and split air conditioners differ in terms of where the heat leaves the room. In the case of a portable air conditioner with an exhaust hose – also known as a monoblock – all the technical components are housed in a unit inside the room; the heat is vented out of the window via the hose. In a split air conditioner, the noisy part – the compressor – is located in the outdoor unit; the indoor and outdoor units are connected by a refrigerant pipe. In between lies the mobile split air conditioner: an indoor unit for placement indoors and an outdoor unit for the balcony or terrace, connected at the factory.

All values on this page are taken from data sheets and the product data in our range; we have not measured or tested the units ourselves. In the context of heat pumps, ‘monoblock’ refers to something else: an outdoor unit that transfers heat to the heating water. These units are not the subject of this discussion.

Information current as at: ACTEC product range, accessed on 12 October 2026. The specifications for individual devices can be found on their respective product pages and in the data sheets provided there.

The biggest difference in everyday use is the noise. With a portable air conditioner fitted with an exhaust hose, the compressor and fan operate inside the room; the manufacturer’s specifications state a sound pressure level of 51 to 54 dB. With a portable split air conditioner, the compressor is located outside, whilst noise levels inside the room range from 39 to 50 dB. The indoor unit of a permanently installed split air conditioner, when mounted on the wall, produces noise levels of 19 to 31 dB, whilst the outdoor unit produces 47 to 59 dB; cassette and floor-standing units have higher noise levels.

Anyone wishing to cool their bedroom should therefore pay particular attention to this figure. As a rule of thumb, the ear perceives 10 dB more as roughly twice as loud. Details on each fan speed setting and the difference between sound pressure and sound power can be found under ‘How loud is an air conditioner?’.

In terms of rated power, the devices are closer to one another than one might think. The difference becomes apparent during operation:

• Inflowing air: The portable air conditioner with an exhaust hose expels room air as exhaust air to the outside. The same volume flows in through doors, joints and window gaps; on hot days, this is warm outside air. A window seal reduces this, but does not prevent it entirely; for information on how to seal the hose and windows, see ‘Portable air conditioner without an exhaust hose?’. With split-system units, the indoor air remains inside the room.
• Different measurement, different scale: For units with an exhaust hose, the EU energy label specifies the EER, measured at a single test point. Split units display the SEER, which reflects performance over the entire cooling season. The classes also start at different points: Class A applies to single-hose units from an EER of 2.6 and to split units from a SEER of 5.1 (Delegated Regulation (EU) No 626/2011). An ‘A’ on a portable air conditioner is therefore not the same as an ‘A’ on a split unit.

Within the product range, the mobile units with an exhaust hose in cooling mode are predominantly Class A with an EER of 2.6 to 2.9, whilst the two TCL models, the TAC-09CPB HE, are Class A++ with an EER of 3.6. The split sets achieve a SEER of 6.1 to 8.5 and are therefore rated A++ to A+++.

For all models, annual consumption is determined by running time, room size and the set temperature. At a power consumption of 1 kW, this amounts to around 1 kWh per hour of cooling operation under rated conditions. For more information, see ‘How much electricity does an air conditioner use?’.

A portable air conditioner with an exhaust hose is set up and connected to a domestic socket; the exhaust hose runs through the sealed window. In the case of a portable split-system air conditioner, the indoor and outdoor units are connected ex works via the refrigerant pipe; the outdoor unit is installed outside, for example on a balcony or terrace. On one of the 12,000 BTU models, the pipe is 2.5 metres long, which limits the distance between the unit and the outdoor unit.

Split air conditioners are filled with a fluorinated refrigerant. For their sale, Article 11(7) of the F-Gas Regulation (EU) 2024/573 and Section 15(3) of the ChemKlimaschutzV require proof that a certified specialist contractor has been commissioned to carry out the installation. This also applies to Quick-Connect sets. You are responsible for commissioning the specialist contractor yourself; installation is not included in the purchase. You can find out how we request proof of this after you have placed your order under ‘Professional installation of your air conditioner’.

A permanently installed split air conditioner requires a wall duct for the refrigerant pipe and a space for the outdoor unit on the façade, balcony or ground. If you are in a rented flat, check with your landlord beforehand; if you own a flat, check with the owners’ association.

Without drilling, there are two types of unit. The portable air conditioner with an exhaust hose requires only a window, which you seal with a window seal. The portable split air conditioner requires a space for the outdoor unit outside; it is quieter indoors because the compressor is located outside.

All split-system units in the range provide heating. According to the data sheet, depending on the model, they operate in heating mode at outdoor temperatures as low as −15, −20 or −25 °C, with a SCOP of 4.0 to 4.7. This means that one kilowatt-hour of electricity generates around four kilowatt-hours of heat.

Of the portable units, only a few models provide heating: the TCL TAC-12CHPB, which features an exhaust hose, and two portable split air conditioners from Hantech with a capacity of 12,000 BTU. They regulate the temperature of a room during the transitional season; they do not replace a heating system. For information on when a split air conditioner can supplement a heating system, see ‘Heating with an air conditioner’.

For the portable air conditioner with an exhaust hose, you will need a window seal; these are also available separately, such as the Hantech window seal (4 m). The portable split air conditioner is operated without installation. With the split set, installation by a specialist firm is required; this is not included in the price and must be arranged with the supplier. The prices of the units are listed on the product pages.

• Permanent cooling, drilling permitted: split air conditioner. Quiet in the room, efficient in operation, also provides heating.
• Multiple rooms: Multi-split air conditioner with one outdoor unit for several indoor units.
• No drilling required, but suitable for balconies or terraces: a portable split air conditioner, without an exhaust hose and quieter than the model with a hose.
• No drilling required, only on individual hot days: portable air conditioner with exhaust hose and window seal.
• Only the air is too humid: a dehumidifier is sufficient; it does not cool.

The section ‘Which air conditioner for which room size?’ shows the capacity required for the room. The units in each class are listed under ‘Air conditioners with 9,000 BTU’ and ‘Air conditioners with 12,000 BTU’.